I'm on my second Sport Trac and love 'em to death too. If you can get by with the short bed, make sure to get one with the bed extender, then it is the Swiss Army knife of trucks.
Mechanically they are identical to Explorers and will run forever. The trannys are sensitive to being flushed regularly and you should do that every 30,000 miles, t-case lube also. If you buy a used one and can't be sure that that's been done, then have the tranny flushed and t-case lube changed immediately. More than 75k on it, I would have the axles done too.
The bed is plastic and pretty much impervious to dents, rust, etc. You can get tonneau covers if it does not have a factory cover. I prefer a vinyl cover because I often need the whole bed open. The factory hard cover is nice but you have to unbolt it to remove it. The seats are vastly better than Ranger seats. '03+ Sport Tracs have 4 wheel disc brakes which are vastly better than Ranger brakes (I've owned Rangers too). The stock shocks on Gen 1 Sport Tracs are way too soft and should be replaced immediately if they are still there. A Gen 1 Trac ('01-'05) is more off-roady than a Gen 2 ('07-'10) and has better ground clearance. Gen 1 4x4's have a t-case skidplate but no fuel tank skidplate although you can get one from Ford Accessories. Gen 2's have no t-case plate but you can get a fuel tank plate from Ford as it was a fleet vehicle option.
Some up-level Tracs have leather interiors, and all of them have a rubber floor mat and not carpet. An aftermarket company did have a carpet kit available a while ago. The Adrenalin model has a hi-zoot Pioneer stereo and subwoofer from the factory.
As far as lifting a Gen 1 Trac, like late-model Rangers and Explorers you are limited to the Superlift suspension lift or a body lift.
If you're looking for a used Gen 1 I would suggest an '03+ to get the 4 wheel discs. If you want a new one, move fast because this is the last year they are making them.
www.mysporttrac.com